Fisetin, also known as (2S)-2-(3,4-dihydroxyphenyl)-7-hydroxy-2,3-dihydrochromen-4-one, is a naturally occurring flavonoid polyphenol. It is found in various fruits and vegetables, such as strawberries, apples, persimmons, onions, and cucumbers. Structurally, it is a flavanol characterized by a 3-hydroxyflavone backbone with multiple hydroxyl substitutions. Its primary significance lies in its broad spectrum of biological activities and pharmacological potential. Fisetin has been extensively studied for its potent antioxidant, anti-inflammatory, neuroprotective, and senolytic properties. Research indicates it can modulate key signaling pathways (e.g., NF-κB, PI3K/Akt) and induce apoptosis in senescent cells. These mechanisms underpin its investigation as a potential therapeutic agent for age-related diseases, neurodegenerative disorders (like Alzheimer's), cancer, and metabolic syndromes. Due to its natural origin and promising bioactivity, fisetin is widely used as a standard reference compound in phytochemical and pharmacological research. It is also a popular ingredient in dietary supplements and nutraceuticals targeting longevity and cognitive health. However, its clinical application is limited by challenges such as poor bioavailability and water solubility, driving ongoing research into novel delivery systems.